pgmenhance(1) pgmenhance(1)
NAME
pgmenhance - edge-enhance a portable graymap
SYNOPSISpgmenhance [-N] [pgmfile]
DESCRIPTION
Reads a portable graymap as input. Enhances the edges,
and writes a portable graymap as output.
The edge enhancing technique is taken from Philip R.
Thompson's "xim" program, which in turn took it from sec-
tion 6 of "Digital Halftones by Dot Diffusion", D. E.
Knuth, ACM Transaction on Graphics Vol. 6, No. 4, October
1987, which in turn got it from two 1976 papers by J. F.
Jarvis et. al.
OPTIONS
The optional -N flag should be a digit from 1 to 9. 1 is
the lowest level of enhancement, 9 is the highest, The
default is 9.
SEEALSO
pgmedge(1), pgm(5), pbm(5)
AUTHOR
Copyright (C) 1989 by Jef Poskanzer.
13 January 1989 1